Chine apparatus for driving and stopping a machine particularly a sewing ma

ABSTRACT

An apparatus for driving and stopping a machine, particularly a sewing machine, comprising, on a shaft carrying a pulley linked directly to the machine and rotatably mounted in a housing, a clutch plate between a fly-wheel driven directly by an electric motor and a wheel driven at a reduced speed. An annular plate is provided which cooperates with the clutch plate to bring it to the fly-wheel, said annular plate having on its opposite face a ring of magnetic material coated on its external face with a lining of friction material for acting with the frontal face opposite the wheel under the action of a coil situated inside the wheel.

United States Patent 1191 Szekely et a1.

1 Sept. 4, 1973 1 APPARATUS FOR DRIVING AND STOPPING A MACHINE, PARTICULARLY A SEWING MACHINE [75] Inventors: Laszlo Szekely, Bruyeres-le-Chatel;

Claude Pigache, Courbevoie, both of France [73] Assignee: SUBEM [22] Filed: Sept. 15, 1971 [21] Appl. No.: 180,662

[52] US. Cl 318/150, 318/45, 318/161 [51] Int. Cl. "02k 7/02 [58] Field of Search 318/45, 150, 161; 310/l()3, 104

156] References Cited UNITED STATES PA'I'ENTS 2,931,928 4/1960 Fehn 318/161 X 3,539,887 11/1970 Dennick 318/45 X Primary Examiner-Bernard A. Gilheany Assistant Examiner-F. E. Bell Attorney-Eric H. Waters [57] ABSTRACT An apparatus for driving and stopping a machine, particularly a sewing machine, comprising, on a shaft carrying a pulley linked directly to the machine and rotatably mounted in a housing, a clutch plate between a flywheel driven directly by an electric motor and a wheel driven at a reduced speed.

An annular plate is provided which cooperates with the clutch plate to bring it to the fly-wheel, said annular plate having on its opposite face a ring of magnetic material coated on its external face with a lining of friction material for acting with the frontal face opposite the wheel under the action of a coil situated inside the wheel.

2 Claims, 2 Drawing Figures APPARATUS FOR DRIVING AND STOPPING A MACHINE, PARTICULARLY A SEWING MACHINE FIELD OF THE INVENTION The object of the invention is an apparatus for driving and stopping a machine, particularly a sewing machine, comprising, on a shaft carrying a pulley linked directly to the machine and rotatably mounted in a housing, a clutch plate between a fly-wheel driven directly by an electric motor and a wheel driven at a reduced speed.

PRIOR ART Devices are known which allow, from an electric motor, the driving of a sewing machine at high speed, or normal working speed, and also at low speed, linking the driving pulley of the sewing machine either to a flywheel driven directly by the electric motor, or to a wheel turning at a reduced speed because of the action of a speed reducer, this being by means of a clutch plate interposed between the fly-wheel and the wheel and acting with the one or the other according to the position of a control means, usually a lever actuated by a pedal.

These known apparatus are generally of complicated construction and it is an objective of the invention to provide an apparatus of this type with a simple construction and a reduced cost.

It is also an aim of the invention to provide such an apparatus whose operation is reliable and particularly convenient to control and which, furthermore, is also well adapted to achieving the stopping of the sewing machine in a predetermined position of the needle.

SUMMARY OF THE INVENTION The apparatus according to the invention is characterised in that the clutch plate is subject to the elastic action of an annular plate tending to bring it to the flywheel, and which has on its opposite face a ring of magnetic material coated on its external face with a lining of friction material for acting with the frontal face opposite the wheel under the action of a coil situated inside the wheel.

In one realised form the said shaft is rotatably mounted in a block of the housing and supports over a bearing a rotatable sleeve subject to the action of springs which take their support from the block and with a longitudinal displacement under the action of the control pedal or the like, said sleeve having on a support a coil whose excitation brings about electromagnetically the braking of the facing pulley.

The description which follows, given as an example, refers to the attached drawings, in which FIG. 1 is a view of part of an apparatus according to the invention with a partial tear-away and section FIG. 2 is a view of another part of the apparatus.

DESCRIPTION OF A PREFERRED EMBODIMENT An electric motor of the usual type, turning for exam-' fixed, by its hub 17, a pulley IS on which runs the driving belt or the like of the sewing machine itself.

On the end of shaft 12 turned towards the electric motor there is fixed a plate 19 which has on its face 20 turned towards said motor a friction lining 21, which is thus opposite the frontal face 22 of the fly-wheel 11. An annular plate 23 of elastic material, metal for example, is also fixed on shaft 12, being held on its inner marginal area between the central part 26 of disc 19 and a shoulder 27 of shaft 12. The plate 23 has on its external part a ring 28 of magnetic material coated, on its face 29 opposite that turned towards the plate 23, with a friction layer 30.

This lining is for acting with the frontal face 31 of a wheel 32 mounted on the block 14 over a bearing 33 and whose opposite face 34 has a ring 35 of electrical insulating material whose external face has two metallic circular concentric tracks 36 and 37 which are linked to a source of electric current. The tracks 36 and 37 are linked electrically through brushes 38 and 39 to the ends of a coil 40 situated inside an annular cavity 42 of wheel 32. V

On the external face 43 of the support 15 are supported springs 44 located in cavities 45 of a sleeve 46 rotatably mounted on shaft 12 over a bearing 47 whose internal case is fixed to said shaft.

To sleeve 46 is fixed a plate 48 bearing an annular receptacle 49 receiving a coil 50 placed opposite a ring 51 of magnetic material with a friction lining acting with the receptacle 49 carried by the pulley 18. The ring 51 is supported in a manner identical to the mounting of ring 28.

Around axle 52 (FIG. 2) carried by support 15 there is rotatably mounted a lever 53 of which a virtually horizontal branch 54 has an arm 55 rotatably mounted around an axle 56 of said lever and has an eye 57 to which is attached the chain or the like 58 which can be actuated by a pedal. The end 59 of the lever 53 on the other side of axle 52 is in the form of a swivel joint 60 engaged in a corresponding cavity 61 of the sleeve. A stop 63 formed on one surface of the vertical portion of lever 53 is adapted to be contacted by an adjustable stop 62 mounted on support 15.

The operation is as follows When the operator presses the pedal, the position of the arm 55 relative to lever 53 is such that a minicontact-breaker in the inside of lever 53 is in a condition whereby the feeding circuit of coil 40 is open. In this position of lever 53, the sliding sleeve 46 is at the right end of its path, it compresses springs 44 and shaft 12, participating in the longitudinal movement of the sleeve 46, is also at the right extremity of its path lining 21 is applied against the frontal face 22 of fly-wheel 11. Plate 19 is driven at the rotation speed of the motor, in the example at 3 000 revolutions per minute, as well as shaft 12 and pulley l8 the sewing machine is driven at high speed.

When the operator releases the pedal, the arm, 55 pivots round the axle 56 and puts into action a minicontact-breaker which applies the feeding current to coil 40. The springs 44 displacethe sliding sleeve 46 from the right towards the left and shaft 12 and lever 53 participate in this movement. When the stop 62 of the support 15 cooperates with the stop 63 on the lever 53, as shown in FIG. 2 of the drawings, the lining 21 moves away from the frontal face 22. The electromagnetic action of coil 40 applies lining 30 against face 31 of the wheel 32. The latter is turning at a low speed, so that the shaft 12 is slowed down and driven at low speed, as also is the sewing machine.

For braking, the feeding current is applied to coil 50. The lining of ring 51 is applied against the frontal face of the annular receptacle 49 and results in a braking'action.

If the braking action is disengaged when the driving means and sewing machine are turning at a predetermined speed and when the fly-wheel itself of the sewing machine is in a predetermined angular position, it is possible to halt the machine for a predetermined position of the needle.

With the apparatus of the invention, the application of current, for example after a period of non-use, leaves the needle in the position which it occupies on stopping.

Also with the apparatus of the invention, it is possible, by pressing the pedal, to put the sewing machine directly at high speed without going through the low speed.

The torque transmitted by the couple for low speed can be very high, the force of application of lining 30 against the frontal face 31 depending on the electromagnetic action of coil 40.

With wheel 32 turning at low speed, the wear on brushes 38 and 39 for feeding the coil 44 is negligeable.

We claim:

1. An apparatus for driving and stopping a sewing machine comprising, a clutch plate supported on a shaft carrying a pulley linked directly to the machine and rotatably mounted in a housing, an electric motor in said housing driving said clutch plate, a fly-wheel driven directly by said electric motor, a wheel driven at a reduced speed connected to said electric motor, said clutch plate being positioned between fly-wheel and said wheel, an annular plate on said shaft exerting at one face thereof an elastic action on said clutch plate so as to bias the latter towards the fly-wheel, said annular plate carrying on its opposite face a ring of magnetic material coated on its external face with a friction lining adapted to cooperate with the frontal face of said wheel, and a coil positioned within said wheel for engaging said lining to cooperate with said frontal wheel face.

2. An apparatus according to claim I, said shaft being rotatably mounted in a block portion of the housing a bearing on said shaft, a rotatable sleeve on said bearing supported by said shaft, springs supported on the block biasing said sleeve with a longitudinal displacement in response to the action of a control pedal, support means on said sleeve, and a coil supported by said support means and having an excitation for electromagnetically effecting braking of said pulley. 

1. An apparatus for driving and stopping a sewing machine comprising, a clutch plate supported on a shaft carrying a pulley linked directly to the machine and rotatably mounted in a housing, an electric motor in said housing driving said clutch plate, a fly-wheel driven directly by said electric motor, a wheel driven at a reduced speed connected to said electric motor, said clutch plate being positioned between fly-wheel and said wheel, an annular plate on said shaft exerting at one face thereof an elastic action on said clutch plate so as to bias the latter towards the fly-wheel, said annular plate carrying on its opposite face a ring of magnetic material coated on its external face with a friction lining adapted to cooperate with the frontal face of said wheel, and a coil positioned within said wheel for engaging said lining to cooperate with said frontal wheel face.
 2. An apparatus according to claim 1, said shaft being rotatably mounted in a block portion of the housing a bearing on said shaft, a rotatable sleeve on said bearing supported by said shaft, springs supported on the block biasing said sleeve with a longitudinal displacement in response to the action of a control pedal, support means on said sleeve, and a coil supported by said support means and having an excitation for electromagnetically effecting braking of said pulley. 